The figure above shows the sea surface temperature anomalies in the tropical Pacific as of December 2019. In the eastern tropical Pacific the SSTs are as higher than normal, signaling an El Nino should be coming! But thus far, the atmosphere has not responded to the warm tropical temperatures. There is a lot of action taking place outside of the tropics with variations in the Polar Vortex that are having a much more profound impact on the weather behavior this winter!
Some El Nino events have brought increased amounts of winter-season precipitation to California and this winter may still bring much more precipitation. However, El Nino is a short-lived event and even enhanced precipiation this winter cannot offset the loss of water resources in California over the past five years of drought.